Abstract: International crude oil prices continued to decline in 2015, approaching MYM30.0 per barrel. This seriously impacts the domestic oil and gas development upstream industry. Offshore oil and gas development known for high cost, high risk, low oil prices in the doldrums makes a great challenge to Bohai drilling and completion, especially for small projects with scattered adjustment wells. On the basis of studying the difficulties and analyzing the cost, through the side drilling and using of domestic rotary steering and longing tools, Bohai oil field has achieved the horizontal well. The overall cost is reduced by 14.7%, and the production reaches 2.2 times the proration before drilling. The effect is significant.